plotutils
plotutils (or The GNU Plotting Utilities) are a set of programs and
functions for drawing and data plotting. They include graph ,
a program for plotting twodimensional scientific data. The programs are
built on top of GNU libplot , a library for deviceindependent
twodimensional vector graphics. graph can display a graph
under XWindows and produce output in several file formats. These include
idraweditable Postscript, output
that may be edited with Xfig, output in
HPGL/2 format for HP printers, output for Tektronix terminals, and
output in the GNU graphics metafile format.
Accompanying graph is a `plot filter' called
plot . It translates deviceindependent GNU graphics metafiles
(produced for example by graph ) into any of the other output
formats.
Among the other programs, spline does spline interpolation of
data. It normally uses either cubic spline interpolation or exponential
splines in tension. Like graph , it can function as a
realtime filter under some circumstances. ode provides the
ability to integrate an ordinary differential equation, or a system of
ordinary differential equations, when provided with an explicit expression
for each equation. It supplements the plotting program gnuplot, which can plot functions but not integrate
ordinary differential equations.
Distributed as a part of this package is GNU libplot , the
underlying function library for deviceindependent twodimensional vector
graphics. It supports all the above output formats. It can draw such
objects as lines, open and closed polylines, arcs, circles and ellipses,
points, and markers. The filling of objects other than points and markers
is supported (fill color, as well as pen color, may be set arbitrarily).
Text strings may be drawn in any of 16 Hershey fonts, 35 Postscript fonts,
and 45 PCL fonts. Cyrillic and Japanese Hershey fonts are included.
